Stablecoin yield comes from one place: the interest earned on the Treasury bills, repos and bank deposits that back every dollar token. The GENIUS Act stops issuers from passing that interest to holders, but it says nothing about the exchanges and apps that pay "rewards." That gap is what the CLARITY Act fight was about. Here's the plumbing, followed one dollar at a time.

On September 15, the Senate voted 49-50 on cloture for the CLARITY Act, the crypto market-structure bill, well short of the 60 votes it needed (CoinDesk, DLA Piper). Ethics provisions were a big hang-up, and so was a question that sounds simple: can someone pay you for holding a stablecoin?

I build stablecoin banking infrastructure for a living. Most coverage of this debate is legal analysis or advocacy, and almost none of it explains where the money comes from. So let's follow one dollar.

Step 1: You hand over $1

You buy one dollar-backed stablecoin. Maybe you wire money to the issuer directly. More likely, you buy it on an exchange or in an app, and the exchange holds the token for you.

Remember that second detail. It ends up mattering most.

Step 2: The issuer mints a token and invests your dollar

The issuer creates one token and puts your dollar into reserves. Under the GENIUS Act, which became law in July 2025, reserves must back outstanding tokens at least 1:1, and they're limited to a short list of safe, liquid assets (Public Law 119-27, Sec. 4):

• Cash, or balances at a Federal Reserve Bank
• Demand deposits at insured banks
• Treasury bills, notes or bonds with 93 days or less to maturity
• Overnight repurchase and reverse repurchase agreements backed by Treasuries
• Government money market funds that hold only the above

Nothing exotic. And everything on that list except physical cash can earn interest.

Step 3: The reserve earns interest

Your token stays at $1. Meanwhile, the dollar behind it sits in T-bills or repo earning short-term rates. The gap between "the token pays you nothing" and "the reserve earns something" is the entire stablecoin business model. When people say "stablecoin yield," this reserve income is the only real source. Everything else is someone deciding how to split it.

Step 4: Who keeps the interest

This is where it gets interesting. The issuer earns the reserve income, but it often doesn't keep all of it. Distribution costs money, and the partners who put the token in front of users want a cut.

The clearest public example is Circle's agreement with Coinbase, described in Circle's 2025 annual report. Payments to Coinbase are figured from net reserve income on USDC. Circle keeps an issuer portion, each side gets an allocation based on how much USDC sits on its platform, and Coinbase gets half of what's left from USDC circulating elsewhere. Circle books these payments as distribution costs (Circle 10-K).

The Congressional Research Service calls this the "three-party model": issuer, exchange, user. The issuer passes reserve interest to the exchange, and the exchange uses it to pay customers "rewards" (CRS, The Stablecoin Yield Debate).

So when an app shows a reward rate on your balance, the money usually traces back to T-bill interest on the reserve.

Why GENIUS bans issuer-paid interest

Section 4 of the GENIUS Act says no permitted issuer "shall pay the holder of any payment stablecoin any form of interest or yield (whether in cash, tokens, or other consideration) solely in connection with the holding, use, or retention" of the stablecoin.

The policy reason is deposit competition. A stablecoin that paid T-bill rates while working like cash would compete directly with bank deposits, which fund lending. Banks argue that interest-bearing stablecoins could drain deposits, especially from community banks. CRS also points to the risks of people moving savings into uninsured instruments that can face runs.

But read the text again. The ban applies to the issuer. As CRS notes, GENIUS doesn't explicitly stop exchanges from paying rewards on stablecoins they hold for customers, and those rewards can be structured to work much like yield. Banks call it a loophole; exchanges call it a product.

The CLARITY fight in one paragraph

The final Senate text of CLARITY tried to split the difference. It would have banned interest or yield on holding a stablecoin while still allowing certain permitted payments that "may be calculated by reference to a balance, duration, tenure," and it would have let Treasury restrict rewards if it found substantial deposit flight from community banks within 18 months of enactment (Mempolitics on the bill text, American Banker). The bill failed, so that compromise isn't law. For now, the issuer ban in GENIUS is the only statutory line.

The engineering view: "rewards" vs "interest" is a ledger decision

Here's what I think gets lost. In software, the difference between interest and rewards isn't a label in the UI. It's a set of design choices that show up in the data model. If I were reviewing a program, these are the questions I'd ask:

1. Who holds the balance? If the issuer's own ledger records what each user owns, any payment on that balance looks like issuer-paid interest. If an exchange holds tokens in an omnibus wallet and keeps its own sub-ledger of customer balances, the exchange is the party paying. Same token, different legal shape, because a different system of record owns the liability.

2. Is the payout a function of time held? A job that runs daily and computes balance × rate × days / 365 is interest by any engineer's definition, whatever the marketing calls it. A payout triggered by an event, like a card purchase, a transfer or a merchant payment, is an activity reward. The CLARITY text explicitly allowed calculations based on balance, duration or tenure, which is exactly why critics said it blessed interest under another name.

3. Who funds it? Trace the money in the general ledger. If a rewards expense account is funded by a monthly payment from the issuer tied to reserve income, the program is economically issuer-funded, even if a third party sends the payouts. The OCC's GENIUS proposal goes right at this: it would presume a violation when an issuer pays an affiliate or "related third party" that then pays yield to holders (Perkins Coie, Davis Polk).

4. Can you prove it? Regulators will ask how each payout was calculated, from which account, under which contract. If your rewards engine can't trace a payout to a qualifying event and a funding source, you can't defend how you classified it.

My takeaway as a builder: the tests regulators are drafting (who pays, what triggers the payment, where the money comes from) are things your database already knows.

What to watch next

• The lame-duck session. The House returns after the midterms. DLA Piper sees further CLARITY progress before the new Congress as unlikely, but a motion to reconsider was entered, so a second cloture vote is procedurally possible (YFarmX). The 119th Congress ends on January 3, 2027.
• Rulemaking. The Fed published its GENIUS proposal on September 29, with comments due November 30 (Federal Register). Treasury issued an interim final rule on state certification procedures on September 30 (Federal Register), and its August 18 proposal on issuance, offer and sale takes comments until October 19 (Federal Register). How the final rules treat affiliate and third-party rewards may matter more than any bill.
• January 18, 2027. That's when GENIUS takes effect, unless final regulations arrive earlier, in which case it's 120 days after them (Fed proposal).

FAQ

Where does stablecoin yield come from? From interest on the reserve assets backing the coin: short-term Treasuries, repo, money market funds and bank deposits. Any yield you see is a share of that income passed along by someone.

Why can't stablecoins pay interest? The GENIUS Act bars permitted issuers from paying holders interest or yield just for holding, using or retaining the coin. The main concern is that interest-paying stablecoins would compete with bank deposits.

What's the difference between stablecoin rewards and interest? It depends on who pays and why. Is the payout based on balance and time held? Is it funded by the issuer's reserve income? Does the issuer hold the ledger? The more "yes" answers, the more it looks like interest.

What does the CLARITY Act say about stablecoin yield? Its final Senate text would have banned yield on holding stablecoins while allowing some payments calculated by balance, duration or tenure, plus a Treasury backstop if community-bank deposits fled. It failed cloture 49-50 on September 15, 2026, so none of that is law.

Is stablecoin interest legal today? Issuer-paid interest is prohibited under GENIUS, which takes effect by January 18, 2027. Third-party rewards are being shaped now by regulators' proposed rules. This is an explainer, not legal or investment advice.

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Views are my own and don't represent my employer. Nothing here is investment, legal or tax advice.